Accurizing A Mosin-Nagant

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Hello,

Author's note: I wrote this in response to a question asked at InGunOwners.com. The responses were such that I thought maybe someone could benefit from it as an article instead of just an answer, so I'm sharing it out as such.

I've been getting asked on the board and via PM how I accurized my MN 91/30.

With all due respect to N_K_1984 and his hard work, I do not believe that the answer lies in floating the barrel. I'll get to that in a minute.

First, torque the action screws to 50in-lbs and shoot the rifle. It may be good the way it is! The PU snipers were just ones pulled from the line because they demonstrated better-than-normal accuracy.

If you're unhappy with the accuracy, you'll need to shim the sear spring/trigger/return spring. They're the same thing. Pull that piece out. While it's out, dress the sear down with a fine stone -- I like to work up to 600 grit for this, but any fine stone should work. Just don't change the angles! Also, stone the area on the sear spring contacted by the trigger. It's all very easy and straightforward.

Next, get a piece of shim stock. It should be 0.020" thick or so. Cut it to fit, drill a hole, and install it between the sear spring and the action. Do not go overboard; you should have an 8lb pull that resembles a revolver trigger. Any less, I consider dangerous, and if it's smooth, it doesn't feel like 8lbs.

Go shoot it. The improved trigger will help you get the inherent accuracy from your rifle.

Now, with regard to the barrel, there are two schools of thought: Floating and bedding. I am usually in the school that says “float”, but the barrel of the Mosin-Nagant is really too thin to float well.

With apologies to N_K_1984, I will pick on his targets because he has the most awesome sporterized Mosin-Nagant I’ve ever seen. However, it needs improvement and this may help him some, too!

target1.jpg
I believe this to be the first target he shot. The reason is that the three-shot group near the bullseye speaks of a cold barrel. However, as the barrel heated up, it threw the last two a bit high.

target2.jpg
In what is probably the second target, you can see how the circle becomes pronounced.

target3.jpg
I am guessing this is the third target shot. It shows a heated thin barrel: It’s shooting large rings.

Floating a barrel is great, but only if it’s not skinny. A fix for this barrel would be a de-resonator about an inch in front of the stock, and a series of o-rings rolled down the barrel to the end, all touching. As is, the circles are not a whole lot bigger because the “cosmetic” thing he has hanging off the barrel’s muzzle is acting a bit like an old BOSS unit (it’s really doing something there, man, not just decoration as you stated in another thread!)

The next option is to bed the barrel.

1. Go to Autozone. Get thin cork gasket material. It should run you about $5.
2. Sand the barrel channel smooth, cut a strip of cork gasket material, and lay it in the barrel channel.
3. Put the barreled action back in, and cut off the excess cork wherever you see any.

Go shoot it. The bedding is allowing the stock and handguard to act as sort of a heavy target barrel. That’s not exactly right, but you won’t be shooting circles and the harmonics will be way down.

Now, bed the action. Just pillar bed (instructions of all sorts are on the Web), heck, I just cut more cork and put it between the points on the action where the screws enter and the stock, then torque to 50in-lb. You just need known pressure points, not random ones.

The rest really depends on the ammo. The 7.62x54r uses .311” bullets, while domestic ammo uses .308” bullets. If you want accuracy, you’re going to have to go with Priv Partisan or S&B. You can reload these cases too, and .311” bullets are readily available as are dies and reloading data. If someone will measure a 7.62x54r from Winchester, please post it. I may be wrong in that it’s still .308, but it was about five years back.

I hope this helps someone.

Josh

Copyright© Joshua M. Smith. I don't give a tinker's damn if you share this out or not; the "©" thing just seems to be in vogue right now! Haha!
 
So, do you bed the entire length of the barrel, or just part of it? How about using the cork tape on the upper handguard as well as the lower?

Interesting idea... I may have to try it.
 
So, do you bed the entire length of the barrel, or just part of it? How about using the cork tape on the upper handguard as well as the lower?

Interesting idea... I may have to try it.

I tried some on the top as well, but it ended up being too thick overall to get the bands back in place.

I've been debating getting some very thin gasket material and doing this, though. The front of the barrel will try to rise, so I have a .020" shim on the front of the handguard.

Josh
 
I epoxy bedded, free floated the barrel, replaced the rear sight with a Mojo and added a Timney trigger to my '42 91/30. It turned it into a rifle that is much more enjoyable to shoot, though I'd be hard pressed to tell you what added the most to accuracy. I tested winchester factory, '55 Bulgarian, Prvi Partisan and .312" Hornady handloads. My 150g Hornady's with Varget were most accurate (1.6" 3 shots 100yds and 3" 10 shots @ 100) with Prvi second most accurate. I really should try shooting it with the handguard off, see if it makes a difference.

I have a 1928 Dragoon Conversion that has a bore of .314". Any hope of finding bullets to load for such a barrel? I got a 2" 3-shot group at 100 with 172 grain Prvi, so I know it can shoot (no modifications to the rifle).
 
I have a 1928 Dragoon Conversion that has a bore of .314". Any hope of finding bullets to load for such a barrel? I got a 2" 3-shot group at 100 with 172 grain Prvi, so I know it can shoot (no modifications to the rifle).

You know, I'm not sure I'd try this... unless you're absolutely sure your chamber dimensions will take it, too...

Josh
 
I'm not sure I understand this, are you saying that my bore diameter is .314" that it could be smaller at the chamber? Or do you mean that loading that size bullet would expand the neck too much and cause high pressure in the chamber?
 
Buy a Finn rifle. I have two that will shoot one inch or better with Privi 150grsp ammo. The only thing I did to the rifles is add a Darrell mounted pistol scope. I have old eyes that cannot see the rear sight any longer due to cateract surgery......Your information is spot on....each rifle is different so trial and error is the exercise of the day.....chris3
 
Buy a Finn rifle.

That's the easiest way, for sure. But you can also take note of some of the Finn fixes. Improved triggers, shimmed actions, heavier barrels.

There's barely any domestically made 54R. The Winchester Metric I've seen is really S&B made and isn't .308".
 
https://www.thehighroad.org/showthread.php?t=56481

attachment.php


If you scroll down in this 2003 post, you will see I posted this pic.

Those layers of tape were an effective trigger job, but the new $100 Timney for Nagants is better.
 
There's barely any domestically made 54R. The Winchester Metric I've seen is really S&B made and isn't .308".

If this is true, then I'll have to grab some!

Back in 2005 or so, they were .308. I measured them.

Josh
 
@ Clark:

Is that epoxy or glass on the bedding job? Looks like it should work well!

I've thought of the Timney trigger, but the MN was designed to be Ivan-proof and I'd like to keep mine -- this particular one, anyway -- simple.

Josh
 
If this is true, then I'll have to grab some!

I just caliper measured my Winchester 180 grain SP rounds. They're right at .310" They work really well in some Mosins, not so well in others. Oddly they don't always work well in Finnish rifles even though they usually have bores right around .310"

Overall I think way too much gets made of bore dimensions with Mosins. There are a lot of other variables, and you just have to shoot a variety and see what a particular rifle likes.
 
Like Rancho, my 91/30 is .314 to .315 and bullets seem to rattle down the bore and then out. I've tried swaging bullets down to .314 but they don't chamber - which is the 'safety' angle where Smith's warning comes from.

The crown was also cut with a dull tool and could also be improved.
 
Joshua M. Smith
I've thought of the Timney trigger, but the MN was designed to be Ivan-proof and I'd like to keep mine -- this particular one, anyway -- simple.
Josh

The Timney trigger is such a big improvement to the 91/30 for sporting applications, that it floats to the top of aftermarket improvements for any gun.

It makes the trigger pull decent, and adds a real safety.
 
Richard Venola had an article in the February issue of Shooting Times and he used a '38 Tula built 91/30. Without the bayonet on it, it shot Silver Bear 185 gr. loads at 1' high and 6" right..........with the bayonet attatched, it shot the same loads at 4.75". 100 yard shots, BTW.

"The '91 was designed and factory sighted for firing with the bayonet fixed"
- Richard Venola
 
Keep in mind that you can drift the front sight as needed to re-zero the Mosin, so whether the factory did it with the bayonet on or off--or did it at all--isn't that big of a deal. In other words you aren't stuck having a bayonet on the thing to get good POI. I always bring the brass tap and hammer when working with a new Mosin.

adds a real safety.

? the Mosin has a real safety
 
I'm not sure I understand this, are you saying that my bore diameter is .314" that it could be smaller at the chamber? Or do you mean that loading that size bullet would expand the neck too much and cause high pressure in the chamber?

Yes, this.

Josh
 
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